(CNN) -- A Pennsylvania man has been sentenced to 45 years in prison in a deadly bank robbery plot -- described by the judge in the case as "incredibly bizarre" -- in which a pizza deliveryman died when a bomb affixed to his neck exploded.

This device held a bomb to the neck of Brian Wells during a 2003 bank robbery in Erie, Pennsylvania.

At the sentencing in Erie, Pennsylvania, prosecutors repeated their contention that the pizza deliveryman was involved in planning the robbery attempt but wore a live bomb only after being threatened by his co-conspirators.

Kenneth Barnes, 55, of Erie, was sentenced Wednesday after he pleaded guilty in September to conspiracy to commit bank robbery and using a destructive device during a crime of violence.

Prosecutors said Barnes and three co-conspirators -- one of whom was pizza deliveryman Brian Wells -- planned to rob a PNC Bank on the outskirts of Erie, and Wells, 46, carried out the robbery on August 28, 2003. Authorities said Wells walked into the bank with a pipe bomb locked to his neck and passed a note demanding money to a teller.

The robbery netted about $8,700.

Wells died when the bomb exploded as he sat in a parking lot after being stopped by police shortly after the robbery.

The case drew national attention and was the subject of intense investigation and questions about whether Wells was a willing participant or a murder victim.

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Prosecutors said after Barnes' sentencing that Wells was involved in planning the robbery but balked when he realized that the bomb he was supposed to wear was real. He was threatened with a gun to make him wear the bomb, according to prosecutors.

U.S. Attorney Mary Beth Buchanan called the sentence "appropriate and just," and said the contentions of Wells' family that he was not involved in the plot are "overwhelmingly" countered by evidence of meetings with Wells, Barnes and the other two co-conspirators before the robbery.

One of the alleged co-conspirators is now dead and the other one, Marjorie Diehl-Armstrong, is undergoing treatment at a federal facility in Texas after the judge in the case found her mentally incompetent to stand trial. Her case will be re-examined by the court next year, said Margaret Philbin, spokeswoman for Buchanan's office.

In sentencing Barnes, U.S. District Judge Sean J. McLaughlin said, "To me, the callousness and complete lack of regard for human life is, in a word, chilling. This case represents the unhappy combination of incredibly bizarre and sadly tragic."